WO2003047835A1

WO2003047835A1 - Fixing device for die platens and/or flange plates of a plastic moulding machine, and plastic moulding machine comprising the same

Info

Publication number: WO2003047835A1
Application number: PCT/EP2002/013338
Authority: WO
Inventors: Klaus Becker; Guido Legewie; David Lequeux
Original assignee: Billion S.A.
Priority date: 2001-12-01
Filing date: 2002-11-27
Publication date: 2003-06-12
Also published as: AU2002364383A1; DE10159118A1; EP1453650A1

Abstract

The invention relates to a fixing device for die platens and/or flange plates of a plastic moulding machine, especially an injection moulding machine, comprising a joint without an axis. The invention is characterised in that the axisless joint (6) essentially consists of a torsion element (6a). In a preferred embodiment, the torsion element (6a) is embodied in a rod-shaped manner, preferably as a round tube, the longitudinal extension thereof (L) being perpendicular in relation to the surface of the die platen (3) or the flange plate (4).

Description

Fastening arrangement for mold mounting plates and / or flange plates of a plastic molding machine, as well as a plastic molding machine

The invention relates to a fastening arrangement for mold mounting plates and / or a flange plate of a plastic molding machine, in particular an injection molding machine, according to the preamble of claim 1 and a plastic molding machine, in particular injection molding machine, with the aforementioned fastening arrangement according to the preamble of claim 7

A tie bar-less injection molding machine with a machine frame, a fixed and a movable mold mounting plate is known from the European patent EP 0 311 133 B2. The fixed mold mounting plate is fastened to one leg of the essentially U-shaped machine frame. On the opposite leg of the machine frame is a fixed cylinder plate is arranged, on which a piston / cylinder of a hydraulic locking mechanism is attached. The closing force that occurs during the spraying process and the driving force between the cylinder plate and the fixed platen is therefore only derived via the machine frame. The movable platen is attached to the piston / Zylιndereιnheιt mounted tiltable about a horizontal axis, so that when the closing force is applied the be movable platen can incline parallel to the fixed platen. In addition, a return spring is arranged in the area of the horizontal axis, which ensures that when the mold is open, the movable platen is returned to the vertical. This is intended to create a tie-bar-less injection molding machine which ensures that the platen parallelism of the mold mounting plates and thus an absolutely tight mold is ensured even when the clamping force is strong.

Furthermore, the European patent EP 0 554 068 B2 describes an injection molding machine with an essentially box-shaped machine frame, on which a fixed platen is attached. Opposed to this mold mounting plate is a movable mold mounting plate, which is slidably supported on the machine frame and on the back of which a piston of a hydraulic piston / cylinder unit rigidly engages. The cylinder housing of this piston / cylinder unit is supported on a pressure plate, which, like the movable platen, is supported on the machine frame. The pressure plate is connected via a joint with a horizontal axis oriented transversely to the direction of movement of the piston / cylinder unit with a leg of a U-shaped bracket. The end of the opposite leg of the bracket is connected to the fixed platen via a corresponding joint. The axes of the joints are aligned centrally with respect to the longitudinal axis of the piston / cylinder unit.

Two brackets are provided, which are arranged laterally next to the machine frame. By means of the articulated support of the fixed platen and the pressure plate, a gaping of the mold halves arranged on the platen under the closing pressure is to be avoided.

A comparable injection molding machine is also known from German patent application DE 44 45 448 A1. Here, the fixed platen and the pressure plate for the piston / cylinder unit are not connected to each other via two but four U-shaped brackets in order to protect the plates from the diverging reaction forces support each other. These U-shaped brackets, which act as tension members, are arranged in pairs on both sides of the machine frame, with one bracket per side being articulated to both plates at an end remote from the frame and the other bracket being connected to both plates at an end closer to the frame. It should also be possible to design the brackets attached to the end of the plates closer to the frame in an almost straight line. A different shape of the brackets near and far from the frame means that their deformation properties in the longitudinal direction of the injection molding machine are different. In order to be able to compensate for this, the frame away from the frame is supported by a piston / cylinder unit on the fixed platen. The compressive force of these additional piston / cylinder units is dimensioned such that the parallelism of the

Plates should always be guaranteed.

A further injection molding machine with an essentially C-shaped machine frame with two frame legs which are also not connected via spars is known from the European patent EP 0 789 648 B1.

A stationary platen is mounted on a frame leg; a flange plate of a locking device is attached to the other frame leg. The locking device essentially consists of a hydraulic piston / cylinder unit and moves the movable platen, which is slidably supported on the machine frame. The

Flange plate and the stationary platen are each attached to the frame legs of the machine frame via so-called holding parts. During the closing process, the holding parts of the flange plate are subjected to tension and those of the stationary platen to pressure. The holding parts are functionally comparable to springs whose elasticity is less than that of the machine frame. In one embodiment, several holding elements are provided, which are distributed over the height of the stationary mold mounting plate and the flange plate and each have a different elasticity, the lower holding parts having a greater elasticity than the upper holding parts. The holding parts are as

Body made of spring steel, the ge by introducing slots become weak. In the lower section, more or deeper slots are provided in order to increase the elasticity accordingly. If the frame legs of the machine frame are now pressed apart during the spraying process, the stationary mold mounting plate and the flange plate can perform a tilting movement relative to the machine frame, whereby the plate parallelism between the mold mounting plates should be maintained. The holding elements thus form an axleless joint, which should also allow translatory movements in addition to rotational movements. The aim of this construction is to avoid the axle mounting of the mold mounting plates known from the prior art.

Furthermore, from the German patent DE 44 20 639 C1, another tie-bar-less injection molding machine with an essentially c-shaped machine frame is known, the basic structure of which corresponds to that described above. In this injection molding machine, however, the flange plate and the stationary platen are each mounted on the legs of the machine frame via upper and lower horizontal bearing axes, which are oriented at right angles to the injection axis. The lower

Bearing axes are at a greater distance from the plates so that elastically deformable compression rods can be arranged between the plates and the bearing axes. This means that the plates can deflect under the injection pressure in the area of the lower bearing axes in order to maintain the plane parallelism of the mold during injection molding. This configuration is intended to offer a solution for reducing the plate deflection by means of asymmetrical internal tool pressures and tearing forces and for automatically compensating for the resulting non-parallelism between the mold halves of the molds.

A tie-bar-less injection molding machine is already described in German utility model DE 94 21 871 U1, the stationary platen of which is fixedly arranged on one leg of the c-shaped machine frame. As previously described in European Patent EP 0 311 133 B2, the movable platen is connected via a joint to a hydraulic piston / cylinder unit, which is supported on one leg of the machine frame. Here, however, the joint is axisless forms and consists of a cuboid body which has incisions from below to create a limited elasticity of the body. The incisions have the shape of right triangles and are in theirs

Alignment alternately introduced into the body.

Proceeding from this, the present invention is based on the object of creating a reliable fastening arrangement for mold mounting plates and / or flange plates of a plastic molding machine, in particular an injection molding machine, and a further plastic molding machine, in particular an injection molding machine, with such a fastening arrangement, which, when the clamping force builds up, ensures the parallelism of the mold mounting plates and thus an absolutely tight tool is guaranteed.

This object is achieved by a fastening arrangement for mold mounting plates and / or flange plates of a plastic molding machine, in particular an injection molding machine, with the features of claim 1. Claim 7 specifies a solution relating to a plastic molding machine, in particular an injection molding machine. Advantageous embodiments of the invention are specified in claims 2 to 6 and 8 to 12.

According to the invention, a fastening arrangement for mold mounting plates and / or flange plates of a plastic molding machine, in particular an injection molding machine with an axleless joint, by designing this axleless joint as an essentially torsion element ensures that the relative movement between the mold mounting plates and / or the flange plates, which is only a few minutes of angle and a machine frame of a plastic molding machine are possible on the one hand and are better controllable on the other. Experience has shown that torsional stresses in the torsion elements according to the invention of the axleless joints according to the known prior art can be calculated more reliably, in particular with regard to their service life. In order to enable the above-described relative movements, the torsion element is on the one hand on the platen or on the flange plate and on the other hand on one Machine frame of the plastic molding machine attached. In a preferred embodiment, the torsion element is rod-shaped, preferably in the form of a round tube, the longitudinal extent of which is oriented transversely to the surface for receiving the mold half of the mold mounting plate or the surface of the flange plate. In the case of vertically oriented mold clamping plates and / or flange plates of a so-called horizontal plastic molding machine, in particular an injection molding machine, the longitudinal extension of the torsion element is oriented vertically.

In a special embodiment, the axleless joint is also provided with a tab in addition to the torsion element, which is fastened to the rear of the platen or flange plate and extends at right angles therefrom. The tab has a hole in which the torsion element is fastened in a rotationally fixed manner. The remaining free end of the torsion element is fastened in a rotationally fixed manner to a machine frame of the plastic molding machine at a distance from the tab. In a further embodiment it is provided that two spaced apart tabs are provided on the platen or flange plate, in the

Bores the torsion element is attached with its ends, preferably welded. The fastening arrangement according to the invention with the torsion element is particularly suitable for use in a plastic molding machine, in particular an injection molding machine, with an essentially U-shaped machine frame, with mold mounting plates and a flange plate. Such injection molding machines are also referred to as three-plate machines. In this case, at least two axleless joints, which are laterally spaced from one another, are then arranged on the fixed platen and the flange plate for the closing drive, in each case in the region thereof facing away from the machine frame.

These joints are preferably located in the corner areas of the plates. It can thus be achieved that the central region of the platen and the flange plate for other components such. B. the locking drive is kept clear. Advantageously, these axless joints arranged on the upper ends of the fixed platen and the flange plate interact with at least one tie rod, which is arranged in the region of the end of the fixed platen and the flange plate facing the machine frame. This creates what is known as a low-profile injection molding machine, which allows largely free access to the mold halves arranged on the mold mounting plates. Preferably two tie rods are provided, each of which is arranged in the lower corners of the fixed platen and the flange plate facing the machine frame. In order to be able to adjust the elasticity of the legs of the c-shaped machine frame and the axleless joints to the elasticity of the tie rods, with the aim of maintaining parallelism between the platen even under high closing pressure, the tie rods are each assigned a spring element that is adjustable.

It is also possible to provide a tie-bar-less injection molding machine with the axleless joints according to the invention. For this are then in the

Corner areas of the fixed platen and the flange plate and arranged on the backs of axleless joints. The elasticity of the upper and lower axleless joints and the elasticity of the legs of the machine frame are coordinated so that the parallelism of the mold mounting plates and thus the mold halves attached to it is maintained even under the high closing pressure.

The plastic molding machine preferably has a machine frame which essentially consists of two U-shaped side parts, at the upper ends of which the legs engage the axleless joints.

The present invention is explained in more detail below on the basis of an exemplary embodiment shown in a drawing. Show it: FIG. 1 shows a side view of a plastic injection molding machine, shown schematically and partially,

Figure 2 is a plan view of Figure 1 and

3 shows an enlarged detail of FIG. 2 from the area of an axleless joint.

FIG. 1 shows a side view of a plastic injection molding machine which is shown schematically and only partially. For the sake of clarity, the clamping unit and the movable platen connected to it, which preferably slide on the tie rods

1 or the machine frame 2 are removed, not shown. A representation of the mold half attached to the fixed platen 3 has also been omitted. In the present case, the illustration of a plastic injection molding machine designed as a so-called three-plate machine was essentially restricted to the machine frame 2, the fixed mold mounting plate 3 and a flange plate 4 for receiving the locking device (not shown).

It can be seen that the machine frame 2 is essentially formed from two c-shaped brackets 2a with upstanding legs 2b (FIG. 1). At the mutually facing inner upper ends of the legs 2b, an axleless joint 6 is attached, on which the flange plate 4 is suspended on the left side and the fixed platen 3 on the opposite right side. The axleless joint 6 engages the upper or the ends of the fixed platen 3 and the flange plate 4 facing away from the machine frame 2. At the opposite ends of the lower or the machine frame 2 facing the substantially rectangular fixed platen 3 and the flange plate 4 are each attached in their corner areas tie rods 1, which additionally support the two plates 3 and 4 against each other. The tie rods 1 are over on one side Spring elements 5 supported on the flange plate 4. These spring elements 5 are adjustable and thus the elasticity of the tie rods 1 can be changed subsequently.

From the further Figure 2, which shows a top view of Figure 1, it can be seen more clearly that two machine frames 2 are provided in the form of side parts spaced laterally from one another, each in the edge regions of the fixed mold mounting plate 3 and the flange plate 4 via the axleless ones Joints 6 are connected to the plates 3 and 4. It can also be seen that the flange plate 4 has a recess and is therefore essentially U-shaped in order to be able to carry out the piston / cylinder unit (not shown) of the clamping unit.

Although the present invention is described on the basis of a so-called three-plate machine, the fastening arrangement can also be used for so-called two-plate machines and other plastic molding machines. It can also be seen from FIG. 2 that the stationary platen 3 and the flange plate 4 are each connected to the legs 2b of the machine frame 2 in their lateral edge areas and in their upper corner areas via the axleless joints 6.

The further FIG. 3 shows an enlarged detail from the area of an axleless joint 6. This axleless joint 6 essentially consists of a torsion element 6a and tabs 6b. In the present embodiment, two laterally spaced tabs are provided, which are screwed to the back of the fixed platen 3 and the flange plate 5, on the opposite of the fixed platen 3 and the flange plate 5

A bore 6c is provided in each end, into which the torsion element 6a is inserted and subsequently welded to the brackets 6b in a rotationally fixed manner. A corresponding bore 2c in the leg 2b of the machine frame 2 is provided in order to guide the torsion element 6a, which is preferably designed as a pipe section, through the machine frame 2 and then to weld it together. The longitudinal direction L of the gate Sionselemente 6a is thus aligned perpendicular to the tabs 6b and perpendicular to the closing direction S of the injection molding machine. In addition, the longitudinal direction L runs horizontally in a horizontal injection molding machine. This alignment of the torsion element 6a compensates for the outward deflection of the legs 2b of the machine frame 2 to the outside by a corresponding yielding of the tie rods 1 as well as the relative movement required between the vertically standing one due to a clamping force applied to the fixed platen 3 and the flange plate 4 fixed mold mounting plate 3 and the flange plate 4 and the leg 2b of the machine frame 2 by appropriate rotation of the torsion element 6a. This relative movement can advantageously be absorbed by this torsion element 6a in a few angular minutes and, compared to a conventional joint with one axis, no lubrication is required.

LIST OF REFERENCES

1 pull rods

2 machine frames

2a bracket

2b legs

2c bore

3 fixed platen

4 flange plate

5 spring element

6 axleless joint

6a torsion element

6b tab

6c bore

L longitudinal direction

S closing direction

Claims

claims:

1. fastening arrangement for mold mounting plates and / or flange plates of a plastic molding machine, in particular an injection molding machine, with an axleless joint,

characterized,

that the axleless joint (6) essentially consists of a torsion element (6a).

2. Fastening arrangement according to claim 1, characterized in that the torsion element (6a) engages on the one hand on the platen (3) or on the flange plate (4) and on the other hand on a machine frame (2) of the plastic molding machine.

3. Fastening arrangement according to claim 1 or 2, characterized in that the torsion element (6a) is rod-shaped, preferably as a round tube, the longitudinal extension (L) transverse to the surface extension of the platen (3) or

Flange plate (4) is aligned.

4. Fastening arrangement according to claim 3, characterized in that the longitudinal extension of the torsion element (6a) with vertically aligned mold mounting plates (3) and / or flange plates

(4) runs horizontally.

5. Fastening arrangement according to one of claims 1 to 4, characterized in that the achless joint (6) next to the torsion element (6a) has a tab (6b) which fastens to the back of the platen (3) or the flange plate (4) and extends from it at right angles, the tab (6b) one Has bore (6c), in which the torsion element (6a) is fixed in a rotationally fixed manner, and the torsion element (6a) is fixed in a rotationally fixed manner at a distance from the tab (6b) on a machine frame (2) of the plastic molding machine.

6. Fastening arrangement according to claim 5, characterized in that two spaced apart tabs (6b) are provided, in the bores (6c) of which the torsion element (6a) is fastened with its ends.

7. plastic molding machine, in particular injection molding machine, with a substantially C-shaped machine frame, with mold mounting plates and a flange plate which are fastened to the machine frame with a fastening arrangement according to one of claims 1 to 6,

characterized,

that at least two axleless joints (6) are arranged on the platen (3) and the flange plate (4) in their area facing away from the machine frame (2), which are laterally spaced apart.

8. Plastic molding machine according to claim 7, characterized in that on the platen (3) and the flange plate (4) in their area facing the machine frame (2) at least two further axleless joints (6) are arranged, which are laterally spaced from each other and their Elasticity greater than that of the existing axleless joints (6).

9. plastic molding machine according to claim 8, characterized in that the spaced oppositely arranged Formauf- Clamping plate (3) and the flange plate (4) are connected to one another in the area of their areas facing the machine frame (2) via at least one tie rod (1).

10. Plastic molding machine according to claim 9, characterized in that two tie rods (1) are provided which are laterally spaced apart.

11. Plastic molding machine according to claim 9 or 10, characterized in that each tie rod (1) is connected to the mold mounting plate (3) and the flange plate (4) at least via an adjustable spring element (5).

12. Plastic molding machine according to one of claims 7 to 11, characterized in that the machine frame (2) consists essentially of two c-shaped side parts, on the legs (2b) of which the axleless joints (6) engage.